Headlight



O. WINSTON.

HEADLIGHT I APPLICATION FILED FEB. 26.4917. 1,355 ,876'. v Patented Oet.19,1920.

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HEADLIGHT.

APPLICATIQN FILED FEB. 26, 1911.

1,355,876. Patented Oct. 19, 1920.

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0. WINSTON. HEADLIGHT.

APPLICATION FILED FEB. 26, 1917.

Patented ()ct.1 9,1920.

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0. WINSTON.

HEADLIGHT. APPLICATIOR FILED ms. 26. 1917.

1,355,876. Patented Oct. 19,1920.

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HEADLIGHT APPLICATION FILED FEB. 26, E917.

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OVER'I'ON WINSTON, 0F MINNEAFOLIS, MINNESOTA.

HEADLIGHT.

Specification of Letters Patent.

PatentedOctJQ, 1920.

Application filed February 26, 1917. Serial No. 150,978.

To all w from it may concern."

Be it known that I, OvnnToN WINSTON, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and tate ofMinnesota, haveinvented certain new and useful Improvements in Headlights; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and nse the same.

My present invention relates to head lights and is particularly directedto an improved form of lens and to an improved relative arrangementthereof, in respect to a concave reflector and an electric light bulbwithin the latter.

The invention is illustrated in the accompanying drawings, wherein likecharacters indicate like parts throughout the several views. Referringto the drawings:

Figure 1 is a vertical section showing a' headlight embodying myinvention, and wherein a two-filament light bulb is employed as a meansfor shifting a light source from the axis of the reflector to a pointvertically above said axis;

Fig. 2 is an elevation looking atthe inner face of the lens;

Fig. 3 is an enlarged fragmentary sectio on the line 33 of Fig. 2;

Fig. 4.- is an enlarged fragmentary view in inner face elevation showinga segmental portion of the lens;

Fig.5 is a longitudinal section taken approximately on the line 5-5 ofFigs. 2 and 1; 1

Figs. (5, 7, 8, 9 and 10 are fragmentary sections taken on the lines6-6, 7--7 8--8, a e and 1o 10 of Fig. 4.;

Fig. 9 is an enlarged section of one of the prismatic sections shown inFig. 9;

Fig. 11 is a view corresponding to Fig. 1, but showing a headlighthaving a single filament light bulb and a slightly modified form oflens;

Fig. 12 is an inner face elevation showing the lens illustrated in Fig.11;

Fig. 13 :is'an enlarged section on the line 13-13 of Fig. 12

Fig. 14; is an enlarged fragmentary view in inner face elevation showinga segmental portion of the lens illustrated in Fig. 13;

Fig. 15 is a section on the line 15-15 of Fig. 14; P r

Figs. 16, 17, 18, 19 and 20 are sections taken respectively, on thelines 16-16, 17-1 7, 18-18, 19-19 and 20-20 of Fig, 1 1; and

Fig. 20 is an enlarged section of one of the prismatic segments shown inFig. 20.

Of the parts of the headlight, the numeral 21 indicates the casing, thenumeral 22 the clamping ring thereof, the numeral 23 the concavereflector, the numeral 24: the electric light bulb, and the numeral 25the lens. The reflector 23 is preferably a hyperbolic reflector and itis provided with an axial passage through which the shank of the bulb 24projects and is held by a suitable support. This bulb support, so far asthis invention is concerned, may be of any suitable construction, but,as shown, comprises a shank engaging sleeve 26 and a tubular socket body27 screwed into a flanged hub 28 secured on the back of the reflector.

The bulb'shown in Fig. 1 is a two-filament bulb, the one filament havingits hot spot at a and the other having its hot spot at Z). The point ais at the axis of the reflector and preferably also at the focal centerthereof. The point I), is vertically above the axis'of the reflector. Bymeans of a threelead circuit 29, 30 and 31,.which includes a battery 32and switches 33 and 34:, either of the two filaments a or b, may, atwill, be energized andused at the lightsource of the headlight.

In Fig. 11 the light bulb 16 is provided with a single filament 0, thehot spot of;

which is at the axis of the reflector and preferably also at the focalcenter thereof. This filament is connected to a battery or source ofelectrical energy 35 by leads 36 in any one of which is a switch 37 l/Vewill now consider the novel construction of the lens, the preferred-formof which is illustrated in the drawings and which, described, is asfollows, and will first con sider the construction shown in Figs. 1 to10, inclusive;

One surface, preferably. the inner surface of the lens is formed withradial prismatic segments of peculiar form. These prismatic segmentsradiate from the center of the lens,- or from the axis of thereflector'and have their? greatest bevel at, or nearest to the'rim ofthe reflector. For'example, assume that the bevel surface of theprismatic segment has an angle of 22 degrees at the rim of thereflector, and that in a direction toward the axis of the reflector,this angle progressively decreases to zero at the said axis. This, as isobvious, produces the greatest thickness in the segments at pointsnearest to the rim of the reflector. All of the said segmental prisms,preferably, have an angle of approximately zero at their innerextremities; but the different prismatic segments, in a directioncircumferentially of the lens, will vary in their maximum angle. In thepreferred arrangement, the maximum angle of the prismatic segments, attheir outer extremities, in a direction circumferentially of the lens,increase progressively from the upper vertical line, down to thehorizontal radial line and below such horizontal line, haveprogressively decreasing angles. In Fig.2, the maximum angle of theprismatic segments, at their outer extremities, are indicated by thesmall numerals marked adjacent thereto.

As already indicated, the beveled surfaces of the prismatic segmentsflare, or diverge from the plane of the reflector in opposite directionsfrom the upper vertical line of the lens. This arrangement produces aminimum downward deflection of the more intense rays from the back orinner portion of the reflector, and a maximum downward deflection of theless intense ra s from the outer portion of the reflector. he generaleffect is to produce a material downward deflection of the light beam.This arrangement, when the light source is at I), gives a good beam forcity street driving.

In the modified form of the lens shown in Figs. 11 to 20, inclusive, aconsiderable portion of the lower part of the lens is left smooth orfree from prismatic lens segments, and while the various prismaticsegments have beveled surfaces that decrease in angle from the rimradially toward the axis of the lens, the decrease in an le is lessrapid than in the previously described construction. For example, thelens segment varyin a maximum of 22 degrees at the rim of the Tens,would decrease toward an angle of approximately 11 degrees at the axisof the lens. Otherwise stated, the several prismatic segments havedecreasing angles from the outer toward the inner portion, varying fromthe said maximum angle to approximately one-half of that maximum angle.

In Fig. 12, the maximum angles of the several segmental prisms at therim of the lens, are indicated by the small numerals marked adjacentthereto.

The beveled surfaces of the prismatic segments that are on oppositesides of the upper vertical line of the lens, incline or bevel inreverse directions, so that they increase the thickness of the prisms inboth directions, circumferentially from the said upper line. Thisdirection of the bevel is important because it causes the rays thatleave the face of the lens to be given a material downward deflection,or, in other words, projection below the radial planes of both thereflected and direct rays. The effect of this is to produce a generaldownward deflection of the light beam, so that a very much greater partthereof, will reach the round than with any lens known to me. Moreover,it is the rays of the beams that ordinarily are projected upward andwhich produce blinding effects, but do not light the road, that are thusmost deflected or refracted, and turned downward onto the road. Thisarrangement also permits a still further improved light effect.Moreover, it is the rays that are most nearly to a horizontal that areven the greatest downward deflection. he exact manner in which thesegmental prisms are distributed may be varied but are preferably asillustrated in the drawings and above described in detail.

With the two filament light bulb or shifting light source shown in Fig.1, there will be the above noted downward deflection of the beam whenthe light source is at point a, but this downward deflection will bematerially increased when the light source is shifted from a to 6.Hence, the shifting light source, in combination with a lens, such asdescribed, makes possible a light beam of long projection, but with amaximum amount of light on the road and a minimum amount of light abovethe road.

An ideal beam for headlights for city street driving is, as alreadyindicated, produced when the light source is at the vertically offsetpoint 6.

In the use of a headlight with an ordinary reflector adjusted so as tothrow approximately the lower half of the light beam upon the ground,which is a quite common arrangement, the lower half of the light beamwill be distributed over many hundreds of square feet of road surface,and per unit of surface, the road will be given but a very smallpercentage of light, as compared with the amount of light thrown uponavertical object in the road, by the upper half of the light beam. Thisis a result just reverse from that desired. An ideal arrangement wouldbe one in which there would be at least as much light per unit ofsurface thrown upon the road as there would upon a vertical object abovethe road; and such an arrangement, obviously, requires very much thegreater part of the light beam to be distributed on the ground and avery minor part of the light beam to be diffused above the road. Thisideal resuit is closely approximated by the use of the improved lensabove described, which, as already stated, produces very great downwarddeflection of the more intense rays of the light beam and diffuses someor a minor par(ti of the less intense light rays above the roa What Iclaim is:

1. A lens for headlights having a group of prisms beveled in the samegeneral direction, the individual prisms, in themselves, in a directionfrom the rim of the lens inward, having decreasing angles to the basalsurface of the lens.

2. A lens for headlights having a group of prisms beveled in the samegeneral direction, which, among themselves, in a directioncircumferentially of the lens, having varying angles to the basalsurface of the lens, the individualprisms, in themselves, in a directioninward from the rim of the lens, having decreasing angles to the basalsurface of the lens. 7

3. A lens for headlights having a group of prisms beveled in the samegeneral direction, which prisms, among themselves, in a directioncircumferentially from the vertical toward the horizontal diameter ofthe lens, have progressively increasing angles to the basal. surface ofthe lens, the individual prisms, in themselves, in a direction inwardfrom the rim of the lens, having progressively decreasing angles to thebasal surface of the lens.

4. A lens for headlights having a group of prisms beveled in the samegeneral direction, which prisms, among themselves, in a directioncircumferentially from the upper toward the lower portion of the lenshave progressively increasing angles to the basal 1 surface of the lens,the individual prisms, in

themselves, in a direction inward from the rim of the lens, havingdecreasing angles to the basal surface of the lens,

5. A lens for headlights having two groups of prisms disposed onopposite sides of its vertical diameter, the prisms in the same groupbeing beveled in the same general direction, and the prisms of differentgroups being beveled in opposite directions, the individual prisms, inthemselves, in a direction inward from the rim of the lens, havingdecreasing angles to the basal surface of the lens.

6. A lens for headlights having two groups of prisms disposed onopposite sides of its vertical diameter, the prisms of the same groupbeing beveled in the same general direction and having, amongthemselves, in a direction circumferentially of the lens, varying anglesto the basal surface of the lens, the individual prisms, in themselves,in

a direction inward from the rim of the lens having varying angles to thebasal surface of the lens.

7 A lens for headlights having two groups of diverging prisms disposedon 0pposite sides of its vertical diameter, the prisms in the same groupbeing beveled in the same general direction and having, amongthemselves, in a direction circumferentially from the upper toward thelower portion of the lens, progressively increasing bevel to the basalsurface of the lens, the individual prisms, in themselves, in adirection inward from the rim of the lens, having progressivelyincreasing angles to the basal surface of the lens.

8. A lens for headlights having radial prismatic segments, the beveledsurfaces of the segments of which have maximum angles to the plane ofthe lens at their outer portions and decreasing angles toward the centerof the lens, the said prismatic segments, in directionscircumferentially of the lens, having progressively varying maximumangles to the plane of the lens.

9. A lens for headlights having radial prismatic segments, the beveledsurfaces of the segments of which have maximum angles to the plane ofthe lens at their outer portions and decreasing angles toward the centerof the lens, the beveled surfaces of the prismatic segments, on oppositesides of the upper vertical line of the lens, diverging from the planeof the lens in opposite directions circumferentially thereof.

10. A lens for headlights having radial prismatic segments, the beveledsurfaces of the segments of which have maximum angles to the plane ofthe lens at their outer portions and decreasing angles toward the centerof the lens, the said prismatic segments, in directionscircumferentially of the lens, having progressively varying maximumangles to the plane of the lens, the beveled surfaces of the prismaticsegments on opposite sides of the upper vertical line of the lensdiverging from the plane of the lens in opposite directionscircumferentially thereof.

In testimony whereof I aflix my signature in presence of two witnesses.

OVERTON WINSTON.

Witnesses:

CLARA DEMAREST, BERNIOE G. WHEELER.

